Conventionally, connectors for electrically connecting circuit boards through metal contacts attached to an insulator are known. In such connectors, phenomena such as solder rising and flux rising, in which solder and flux used for attaching the contacts to the circuit boards creep up, are known. If the solder and flux creep up the contacts and harden, contact failure between the contacts occurs, resulting in connector product defects. Therefore, several methods for suppressing solder rising and flux rising have been disclosed.
For example, Patent Literature (PTL) 1 discloses a connector for connecting flexible printed circuit boards (FPC). The connector forms a region in which metal plating is not applied and the material surface is exposed on the surface of each contact. Thereby, a region having low wettability with respect to solder and flux is formed in this connector, and thus solder rising and flux rising are suppressed.
PTL 2 discloses a connector for electrically connecting printed circuit boards. In this connector, Ni plating is applied to a part of the surface of each contact. Thereby, a region having low wettability with respect to solder and flux is formed in this connector, and thus solder rising and flux rising are suppressed.